The present invention relates to a sacking connection for filling open-top sacks with dusty products, with two spreading flaps that can be pivoted around horizontal axes and with which are associated clamping jaws that can be pivoted around horizontal axes and hold the edge of the opening of the sack against the spreading flaps.
A sacking connection of this type is known from German Patent No. 1 948 229.
There are several problems involved in filling open-top sacks with dusty products. Aside from the effects on the environment that such products can have, especially if they are chemicals, there is a risk that the edge of the sack cannot be sealed reliably enough or only by expensive means because of dust buildup in the vicinity of the closure seam. The dust problem can lead, when plastic sacks are being sealed, for example, to the necessity of cleaning the inside surface of the closure-seam zone manually or mechanically, which can, however, depending on the type of dust and its chemical composition, still not be effective enough in many cases for the sack to be reliably sealed with a closure seam.
When the inside of the vicinity of the closure seam gets contaminated, it could result in a welded seam of a quality too poor to seal the sack. It may for example be necessary to clean the inner surface of the sack in the vicinity of welded seam that is to be applied, which entails additional expense.
The only alternatives, consequently, are to seal the sacks with a separately applied rider tape or to utilize valve sacks instead of open sacks. Both possibilities are, however, uneconomical because additional equipment is needed to apply the rider tape and because valve sacks are essentially more expensive to manufacture than open sacks.
Along with the need to solve the dust problem, however, there is that of achieving a loading efficiency equal to that of comparable but non-dusty products.
Further, the closure-seam area of sacks with folding sides cannot be mechanically cleaned. If the sides are not unfolded during the filling process the loading efficiency will be correspondingly low.